Abrasive articles such as coated abrasive articles and bonded abrasive articles contain abrasive particles retained in a binder (or bonding material). The effectiveness of various abrading properties of abrasive articles may depend in part on the orientation and/or placement of the abrasive particles. This may be especially true in the instance that the abrasive particles have a non-random, predetermined shape. It would be useful to have new methods of making abrasive articles that are capable of effectively orienting and positioning the abrasive particles.
The orientation of abrasive particles with respect to the cutting direction is also important. The cutting efficiency and abrasive particle fracture mechanism varies with orientation. With triangular shaped abrasive particles, for improved cut and breakdown, it is generally preferred that the abrasive article and/or workpiece relative motion is such that the edge of the triangle is presented in the motion of cutting instead of the triangle's face. If the triangular face is presented to the direction of cutting, often the triangle will fracture near the base and out of the plane of grinding.
The spacing of the abrasive particles in an abrasive article can also be important. Conventional methods such as drop coating and electrostatic deposition provide a random distribution of spacing and grain clustering often results where two or more shaped abrasive particles end up touching each other near the tips or upper surfaces of the shaped abrasive particles. Clustering leads to poor cutting performance due to local enlargement of bearing areas in those regions and inability of the shaped abrasive particles in the cluster to fracture and breakdown properly during use because of mutual mechanical reinforcement. Clustering creates undesirable heat buildup compared to coated abrasive articles having more uniformly spaced shaped abrasive particles.